Extensive use of communication is most likely to aid in solving complex problems.

i dont know sorry why dont you looking it up on google

on the first day of new student week, amber revealed to her roommate that she is a lesbian. this is an example of self-disclosure.

d. i assume the underlined word is "role." reformat if it isn't.

explanation:

role is closest to part because when replacing words, "playing a vital decision," "playing a vital activity," and "playing a vital dollar" don't make logical sense. the only meaningful choice is "playing a vital part."

this fits one of merriam-webster's definitions of role: "a function or part performed especially in a particular operation or process."